Routine structural analysis by X-ray crystallography has played an important role in the significant developments in inorganic chemistry, biochemistry, and molecular biology in the past two decades. The crystallographic equipment secured through this grant will be employed in a number of areas of contemporary interest to the general chemical community: 1. The study of structure-function relationships in MO-S complexes relevant to the molybdoenzymes. 2. The investigation of Cu(I) and Cu(II) species related to the copper "blue" proteins and dimeric copper species of general catalytic interest. 3. Solid-state conformations of nucleotides and nucleosides. 4. Structural relationships in modified cytochrome-c proteins. 5. Structural properties of intercalating systems and nucleic acid-drug interactions. The ability to perform definitive structural investigations with state-of-the-art crystallographic equipment will facilitate these studies and enhance the quality and efficiency of the efforts in these areas.